2013/09/29 by Hongming Weng, Xi Dai, Zhong Fang · 2 citations
Physics and Astronomy · #cond-mat.mtrl-sci #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevx.4.011002
published as Phys. Rev. X 4, 011002 (2014) · 16 pages, 6 figures
arxiv created 2013/09/29 · arxiv updated 2014/01/17
Quantum spin Hall (QSH) insulators, a new class of quantum matters, can support topologically protected helical edge modes inside bulk insulating gap, which can lead to dissipationless transport. A major obstacle to reach wide application of QSH is the lack of suitable QSH compounds, which should be easily fabricated and has large size of bulk gap. Here we predict that single layer ZrTe5 and HfTe5 are the most promising candidates to reach the large gap QSH insulators with bulk direct (indirect) band gap as large as 0.4 eV (0.1 eV), and robust against external strains. The 3D crystals of these two materials are good layered compounds with very weak inter-layer bonding and are located near the phase boundary between weak and strong topological insulators, which pave a new way to future experimental studies on both QSH effect and topological phase transitions.